Marijuana Health Article

MARIJUANA AND SUBSTANCE ABUSE

Since the 1970s, research has consistently demonstrated that adolescents progress through a uniform sequence of drug use involvement that begins with alcohol, cigarettes, and marijuana and proceeds to the use of "hard" drugs like hallucinogens, benzodiazepenes, amphetamines, sedatives, cocaine, and heroin. For this reason, marijuana, alcohol, and tobacco have been called "gateway" drugs. Some studies have shown that use of marijuana is almost a necessary condition for cocaine use by youth. The more frequently and intensively that gateway drugs are used, the greater the likelihood of dependence on the drug and progression to a later stage in the sequence of substance use involvement. However, most young people who use marijuana do not progress to dependence, or use harder drugs. The majority of marijuana users do not use other illicit drugs, although they are more likely to smoke cigarettes and drink alcohol than nonusers. Heavy use of marijuana does, however, place users in contact with more diverse networks of drug users and sellers, thereby increasing their exposure to other drugs and to the influence of those who use them. Participation in street culture is related to marijuana use. Those young people who do progress to abuse other illicit drugs and who experience the most harmful consequences are more likely to be socially and economically disadvantaged.

PREVENTION

Most cannabis-use prevention programs are school based, and they tend to focus on illicit drugs in general, not just marijuana. The existence of a stable pattern of drug use suggests that prevention efforts should be directed not only at preventing the initiation of use, but also at curbing the transitions from experimental to regular use of any of the gateway drugs and the transition to other drugs. In reviewing what works in drug-use prevention, D. R. Gerstein and L. W. Green found that no prevention programs were reliably effective in all cases with all groups. However, a number of principles for effective prevention have been identified. The U.S. National Institute on Drug Abuse suggests that programs should be comprehensive and long-term, with reinforcement over several years; should target all forms of drug abuse; focus on the family, with a parent or caregiver component; include interactive methods, and be age-specific, developmentally appropriate, and culturally sensitive. School programs are best offered in the sixth through tenth grade, and should include components to develop interpersonal social skills, resistance skills, and self-efficacy, and to improve knowledge of health effects. The higher the level of risk in the specific population, the more intensive and targeted the program should be.

MARJORIE A. MACDONALD

(SEE ALSO: Addiction and Habituation; Behavior, Health-Related; Health Promotion and Education; School Health; Social Determinants; Substance Abuse, Definition of)